#include<bits/stdc++.h>
using namespace std;

int main()
{
    string s;
    cin>>s;
    int n = s.length();
    bool ok = true;
    for(int i = 0;i<n/2;i++)
    {
        if(s[i]!=s[n-1-i])
        {
            ok = false;
        }
    }
    if(ok==true)
    {
        printf("YES\n");
    }
    else
    {
        printf("NO\n");
    }
    
}